Dissolved oxygen (DO) concentrations showed a striking pattern in a multi-year study of the River Enborne, a small river in SE England. In each of three years (2010-2012), maximum DO concentrations were attained in mid-April, preceded by a period of steadily increasing diurnal amplitudes, followed by a steady reduction in both amplitude and concentration. Flow events during the reduction period...

The identification and estimation of discrete-time models of BOD-DO (Biochemical Oxygen Demand-Dissolved Oxygen) in river systems is considered using a multivariable extension of the instrumental variable approximate maximum likelihood techniques of time series analysis. The dynamic water quality models relate water quality at specific points on the river and are used in a design study to evalu...

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investigating nozzle’s orifice flow is challenging both experimentally and theoretically. this paper focuses on simulating flow inside diesel injector nozzle via ansys fluent v15. validation is performed with experimental results from winkhofler et al (2001). several important parameters such as mass flow rate, velocity profiles and pressure profiles are used for this validation. results includ...

LIDAR is relatively new in the commercial market for remote sensing of topography and it is difficult to find objective reporting on the accuracy of LIDAR measurements in an applied context. Accuracy specifications for LIDAR data in published evaluations range from 1 to 2 m root mean square error (RMSEx,y) and 15 to 20 cm RMSEz. Most of these estimates are based on measurements over relatively ...

We developed an individual-based model (IBM) to understand the effects of hydropeaking on growth, survival and distribution age 0+ 1+ juveniles for high-conservation value populations native brown trout (Salmo trutta) Atlantic salmon (S. salar) in river Gullspång, Sweden. parameterized applied inSTREAM (7.2-SD) calibrated by comparing predicted versus observed growth under current regime (n=>1,...

Representing peak and off-peak energy prices is often difficult in hydropower modeling because the time scale of price variability (hours or less) is much shorter than that needed for many operations planning models (days to months). This work extends and examines the reliability of an existing approximate method to incorporate hourly energy price information into revenue functions used in hydr...

A new version of the Integrated Nitrogen in Catchments model (INCA) was developed and tested using flow and streamwater nitrate concentration data collected from the River Kennet during 1998. INCA is a process-based model of the nitrogen cycle in the plant/soil and instream systems. The model simulates the nitrogen export from different land-use types within a river system, and the in-stream ni...

The basic premise underlying ecohydraulics is deceptively simple: create a new discipline focused on the effects of water movement in aquatic ecosystems by melding principles of aquatic ecology (including aspects of fluvial geomorphology) and engineering hydraulics. However, advancing ecohydraulics as a synthetic, organized field of study is challenging because hydraulic engineers and ecologist...